Systems for supplying, distributing and handling pressurized fluids such as pressurized fuel are widespread in the internal combustion engine and machinery fields. For certain engines, notably compression ignition engines, a pressurized fuel system is often used for delivering combustible fuel to individual cylinders by way of fuel injectors. The relatively high pressures of the fuel can assist in atomization of fuel spray to various ends, notably efficiency and reduction of certain emissions. The mechanisms used for pressurizing the fuel, distributing the fuel to individual fuel injectors, and containing fuel throughout the system under relatively high pressures tend to be robust and highly sophisticated. Fuel pressures in some modern systems can exceed 300 MPa.
Decades ago engineers developed so-called common rail fuel systems where a fuel reservoir is maintained at or close to a desired pressure. A plurality of individual fuel injectors fluidly connected to the common rail can be supplied with the fuel at rail pressure and selectively operated to effect fuel injection. Certain variations on the basic common rail design have been developed more recently, including systems where a plurality of separate fuel accumulators are positioned fluidly between a common rail and each of a plurality of fuel injectors. Certain other systems can include variations on these general themes.
As noted above, pressurized fuel system equipment tends to be sophisticated, and components such as pumps, seals, fluid conduits and the like are generally relatively robustly designed. For various reasons, one of which is the tendency for cavitation of the liquid fuel to occur, the high pressure fuel system environment can be relatively harsh, and component service lives are therefore commonly short. Commonly owned U.S. Pat. No. 6,647,966 to Ye Tian teaches a typical common rail fuel injection system.